Add textobjects and indents to c and cpp (#1293)

Indentation of single line statements doesn't work, i.e.

  for (;;)<hit enter>
leads to
  for(;;)
  <cursor here>

Only blocks with curly braces are indented.

runtime/queries/c/textobjects.scm

@@ -0,0 +1,13 @@
+(function_definition
+  body: (_) @function.inside) @function.around
+
+(struct_specifier
+  body: (_) @class.inside) @class.around
+
+(enum_specifier
+  body: (_) @class.inside) @class.around
+
+(union_specifier
+  body: (_) @class.inside) @class.around
+
+(parameter_declaration) @parameter.inside